Abnormal Hippocampal Blood Flow Persists in Gulf War Vets

TUESDAY, Sept. 13 (HealthDay News) -- For Gulf War veterans with specific syndromes, abnormal hippocampal blood flow persists, and in some cases worsens, 11 years after initial testing, according to a study published online Sept. 13 in Radiology.

Xiufeng Li, Ph.D., from the University of Texas Southwestern Medical Center in Dallas, and colleagues investigated whether abnormal hippocampal blood flow in ill Gulf War veterans persisted 11 years after initial testing with single photon emission computed tomography, using arterial spin labeling (ASL) perfusion magnetic resonance imaging and physostigmine challenge. Veterans were divided into three illness groups: syndrome 1 (impaired cognition), syndrome 2 (confusion-ataxia), and syndrome 3 (central neuropathic pain), and a control group. Participants in all the groups were infused intravenously with saline in an initial session and physostigmine 48 hours later. Hippocampal regional cerebral blood flow (rCBF) was measured with pulsed ASL after each infusion. Differences in rCBF after the cholinergic challenge across the four groups were determined by a mixed-effects linear model, after adjusting for age.

The investigators found that physostigmine infusion significantly reduced hippocampal rCBF in veterans in the control group and in those with syndrome 1, whereas a significant increase was observed in hippocampal rCBF in veterans with syndromes 2 and 3. The abnormal increase in rCBF progressed to the left hippocampus of veterans with syndrome 2 and to both hippocampi of veterans with syndrome 3.